Many illnesses can cause headaches, nausea, fatigue, dizziness, and stomach pain. It is difficult to narrow down the specific condition someone may have based on symptoms alone. A doctor can provide a proper diagnosis.

These symptoms may also be interlinked. For example, someone may experience a headache and dizziness due to changes in their head. Stomach pain may be due to nausea. Fatigue may result if someone is tired due to pain.

There are many possible causes for these symptoms, so it is essential for people to contact a doctor and avoid self-diagnosing. This way, a person can get the most accurate diagnosis and receive appropriate treatment.

This article explains some possible causes of headaches, nausea, dizziness, fatigue, and stomach pain, including gastroenteritis, migraine, and COVID-19. It also advises when to contact a healthcare professional for each possible cause.

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Gastroenteritis results from inflammation of the stomach and intestines. Different conditions can cause gastroenteritis, including viruses such as norovirus and bacterial infections such as Salmonella. Some people refer to viral gastroenteritis as “stomach flu.”


A person with gastroenteritis may experience:

Headaches can be a symptom of dehydration resulting from the gastroenteritis infection itself. They may also occur due to muscle stiffness from vomiting or staying in bed for long periods.

Dizziness may occur because of lost fluids from diarrhea or vomiting.

What to eat with stomach flu.

When to contact a doctor

Most cases of gastroenteritis are viral and resolve on their own.

However, if a person shows signs of dehydration or the illness worsens, they should contact a healthcare professional. Symptoms of dehydration or severe gastroenteritis may include:

Treatment of gastroenteritis may involve antibiotics if the doctor suspects a bacterial cause. Young children, older adults, or pregnant people will require intensive rehydration.

Learn more about the signs of dehydration.

Sometimes, people experience headaches, nausea, dizziness, fatigue, and stomach pain during pregnancy.

Some individuals may develop these symptoms in early pregnancy as pregnancy hormone levels rise. However, symptoms can occur at any stage.


A person who is pregnant may experience:

When to contact a doctor

A person may often expect these symptoms during pregnancy. However, it is important for individuals to tell a doctor about all symptoms and ask about treatment options for those that disrupt daily life.

If someone experiences severe dizziness, a headache so intense it is unbearable, or cannot keep any food down, they should seek care right away.

Some people find relief from pregnancy symptoms by avoiding certain foods, drinking more water, or resting.

Learn more about what to expect during pregnancy.

Migraine is a chronic condition. Many people who have migraine experience it often during their lives.


A migraine headache is a type of neurological headache that causes:

  • moderate to severe headache on one side of the head
  • pulsating head pain
  • worsening pain during routine physical activity
  • nausea or vomiting
  • sensitivity to light and sound

Some people also experience unusual sensations, such as strange lights or sounds.

When to contact a doctor

Migraine is not dangerous. However, if a person experiences the following symptoms alongside a migraine headache, they should contact a doctor:

Identifying migraine triggers can help a person avoid headaches. A doctor can also prescribe a wide range of medications, including those that can prevent or treat migraine.

Read more on when to worry about a headache.

Cold and flu viruses are common respiratory illnesses, but they differ due to the virus that causes them. The flu could lead to more serious health complications, such as pneumonia.


People with the cold or influenza virus may develop the following symptoms:

Symptoms of the flu tend to be more severe, last longer, and may come on suddenly.

When to contact a doctor

Both the cold and flu are viruses that usually resolve on their own. However, a person should contact a doctor if they experience:

  • difficulty breathing
  • ongoing chest or stomach pain or pressure
  • ongoing dizziness or confusion
  • seizures
  • severe muscle pain
  • extreme weakness
  • fever or cough that goes away and comes back or worsens

People should drink plenty of fluids, rest, and stay home to avoid transmitting the virus.

How to treat a cold or flu at home.

The novel coronavirus causes COVID-19, which is a respiratory illness. Symptoms can be severe or moderate, or a person may not notice them.


A person experiencing symptoms of COVID-19 may notice:

Learn the difference between COVID-19, cold, and flu symptoms.

When to contact a doctor

A person should seek emergency medical care if they experience the following symptoms:

  • difficulty breathing
  • chest pain or pressure that does not go away
  • new confusion
  • difficulty staying awake or waking up
  • pale, blue, or gray hues to their skin

People with concussion may have recently had a blow to the head, such as from a fall or car accident.


A head injury can cause a headache, as well as neurological symptoms such as:

  • dizziness
  • vomiting
  • nausea
  • confusion

Learn about the symptoms of concussion.

When to contact a doctor

Treatment depends on the severity of the injury. However, a doctor may need to keep a person in the hospital for monitoring.

Depending on the nature of the head injury, a person might need ongoing support or rehabilitation, such as occupational therapy.

A stroke happens when something, such as a blood clot, blocks blood flow to the brain.


The symptoms of a stroke vary from person to person and may change based on which area of the brain a stroke affects. Some people experience nausea, dizziness, or vomiting.

The most common symptoms of a stroke include:

  • inability to raise both arms to the same level
  • one side of the face drooping, especially when a person smiles
  • severe headache
  • changes in speech, especially not being able to repeat words
  • sudden weakness or numbness on one side of the body

When to contact a doctor

A person should go to the emergency room or call 911 immediately if they notice these symptoms in themselves or someone else. Delaying care can result in death.

There is no safe home treatment for a stroke. A doctor may perform surgery, admit a person to the hospital, or recommend long-term care, such as physical or speech therapy.

As the brain controls much of what the body does, neurological conditions can cause symptoms such as nausea, dizziness, and a headache.

Although rare, the appearance of these symptoms together may signal another neurological condition, such as a brain tumor.

Only a doctor can properly diagnose a neurological condition, so it is important to consult a neurologist for any unexplained symptoms that do not resolve with home treatment.

The treatment for these symptoms will vary depending on the underlying cause.

Learn about different types of headaches.

Below are some common questions about these symptoms.

What causes dizziness, headaches, nausea, and fatigue?

A huge range of conditions can cause these general symptoms, including the common cold, pregnancy, and COVID-19. People should speak with a doctor or another healthcare professional for a proper diagnosis.

What deficiency causes headaches and fatigue?

Deficiencies in iron and vitamin B12 can lead to anemia, which can cause fatigue and headaches, among other symptoms.

People can consult a healthcare professional if they suspect they have a nutritional deficiency.

Headaches can be worrying, and nausea can make even basic daily functions difficult — especially if someone also experiences dizziness, stomach pain, and fatigue.

However, in many cases, symptoms go away on their own or occur due to a minor illness, not because of a major health crisis.

In addition to the conditions above, there are many possible causes of these symptoms. A person should discuss their symptoms and history with a doctor for a proper diagnosis.

It is important to contact a doctor as soon as possible if these symptoms do not resolve on their own or worsen or if there are additional symptoms.